Our orbital velocity is seven hundred thousand kilometers per second!
The variation in the orbital velocity of some comets is enormous.
But, because of it's great mass, our orbital velocity is something terrific!
But what they couldn't do was match its orbital velocity, which was zero.
At the orbital velocity of the ship, focussing on the star was indeed a difficult thing to do.
But the closer the massed wreckage dropped toward Earth, the higher were its requirements for orbital velocity.
Its orbital velocity, I later computed, was some twenty-two miles a second.
In many cases the orbital velocity has been approximately ascertained.